How to turn off Rails caching during development

Question

I'm on Rails 5.2.2 and I'm building a web app that uses some static HTML, CSS, and JavaScript that I'm serving from inside of the public directory. Much of the time when I update a file it doesn't update in my browser when I refresh, but if I go into private browsing it works -- until it caches again and then I need to open a new private window.

How can I turn off caching for file in the public folder? Or if it's easier, how can I turn off all caching during development?

This is what my development.rb looks like. I tried commenting out the entire if Rails.root.join('tmp', 'caching-dev.txt').exist? block but that didn't do anything.

I'm also open to installing a gem to solve this if it can't be fixed with a setting.

Rails.application.configure do
  # Settings specified here will take precedence over those in config/application.rb.

  # In the development environment your application's code is reloaded on
  # every request. This slows down response time but is perfect for development
  # since you don't have to restart the web server when you make code changes.
  config.cache_classes = false

  # Do not eager load code on boot.
  config.eager_load = false

  # Show full error reports.
  config.consider_all_requests_local = true

  config.file_watcher = ActiveSupport::FileUpdateChecker

  # Enable/disable caching. By default caching is disabled.
  # Run rails dev:cache to toggle caching.
  if Rails.root.join('tmp', 'caching-dev.txt').exist?
    config.action_controller.perform_caching = true

    config.cache_store = :memory_store
    config.public_file_server.headers = {
      'Cache-Control' => "public, max-age=#{2.days.to_i}"
    }
  else
    config.action_controller.perform_caching = false

    config.cache_store = :null_store
  end

  # Store uploaded files on the local file system (see config/storage.yml for options)
  config.active_storage.service = :local

  # Don't care if the mailer can't send.
  config.action_mailer.raise_delivery_errors = false

  config.action_mailer.perform_caching = false

  # Print deprecation notices to the Rails logger.
  config.active_support.deprecation = :log

  # Raise an error on page load if there are pending migrations.
  config.active_record.migration_error = :page_load

  # Highlight code that triggered database queries in logs.
  config.active_record.verbose_query_logs = true

  # Add devide default mailer url
  config.action_mailer.default_url_options = { host: 'localhost', port: 3000 }


  # Raises error for missing translations
  # config.action_view.raise_on_missing_translations = true

  # Use an evented file watcher to asynchronously detect changes in source code,
  # routes, locales, etc. This feature depends on the listen gem.
  config.file_watcher = ActiveSupport::EventedFileUpdateChecker
end

Answer 1

It's not rails who caches, it's your browser.

Either you explicitly set

config.public_file_server.headers = {
  'Cache-Control' => "no-cache"
}

(and clean your browser cache, who has all old and valid versions of your files), or you disable browser cache completely.